Toggle spring actuating means



April 11, 1944. w. E. STILWELL, JYR 2,346,544

TOGGLE SPRING AGTUATING MEANS Filed July 8, 1942 2 Sheets-Sheet l I z5.j. @4 15. Z \9 k3 INVENTOR. w/zm E. 57/114/511, JA

April 11, 1944.

WQE. STILWELL, JR

TOGGLE SPRING ACTUATING MEANS Filed July 8, 1942 2 Sheets-Sheet 2 INVENTOR.

\ W/ZZ/ M EST/LWELLJ Q O/QNEY Patented Apr. 11, 1944 UNITED STATES PATENT OFFICE TOGGLE SPRING ACTUATING MEANS Application July 8, 1942, Serial No. 450,138

16 Claims.

This invention relates to improved toggle springs and actuating means therefor.

In particular, this invention relates to toggle spring actuators, comprising plunger means moved into engagement with the toggle spring to exert a pressure thereagainst.

It is an object of the invention to provide an improved toggle spring actuating means which is remotely controllable.

It is an object of the invention to provide improved toggle spring actuating means comprising a plunger system arranged to exert a flipping force on a toggle spring over a continuing path which is less than the total distance of throw of the toggle spring.

It is an object of the invention to provide toggle spring actuating means comprising a plunger system adapted to exert a continuing pressure on said toggle spring over a path equal to less than fifty per cent (50%) of the total distance of throw of said toggle spring.

It is an object of the invention to provide toggle spring actuating means wherein the force exerted on said toggle spring terminates before the fulcrum plane of said toggle spring is reached.

It is an object of the invention to provide an improved toggle spring actuator in which opposed plunger systems are adapted for simultaneous movement in the direction of said toggle spring, only one of said plunger systems exerting a force on said toggle spring during said simultaneous movement.

It is an object of the invention to provide improved toggle spring actuating means comprising a plurality of plunger systems operable by simultaneously energized, remotely-controlled magnet systems.

It is an object of the invention to provide improved toggle spring actuating means comprising a plurality of solenoid-controlled armature systems wherein the solenoids thereof are energized through a two-wire control circuit common to the solenoids, without recourse to ratchets, switch means, or like apparatus commonly employed to connect the solenoids alternately into the control circuit.

The improved actuating means for toggle springs is particularly adapted for installations wherein the movement of the toggle spring operates mechanical apparatus or the like. In the illustrated embodiment of the invention, the toggle spring is organized to operate as a remote-control electric circuit breaker.

In my presently co-pending application Serial No. 441,382, filed May 1, 1942,. and entitled Toggle springs, there is disclosed an improved toggle spring comprising a concatenation of. spring systerms of respectively different spring characteristics. A feature of operation of said toggle spring is that the application of force to said spring over a distance comprising less than fifty per cent (50%) of the total extent of throw of the spring,

creates certain internal forces within the spring which are effective to complete the throw of the spring without additional external force application. The throw of the toggle spring is from concave to convex form, and the extent of throw is substantially uniform.

In a preferred embodiment of the instant invention, strikers are disposed on opposite sides of a toggle spring, and are arranged to be simultaneously moved in the direction of the spring. Because of the initially concave or convex configuration of the spring, its center portion will be closer to one of the pair of opposed strikers. During the simultaneous movement of the strikers toward the spring, the striker which, by reason of the configuration of the spring, is closer thereto, will exert pressure upon the spring, to initiate its movement to its oppositely curved position. The extent of movement of the striker after it has initially impinged against the spring is limited to less than fifty per cent (50%) of the throw of the pring, whereupon the spring continues its throw under its own internal energy. During the latter part of such throw, it may strike against the opposed striker, to forcibly carry said striker in the direction of throw.

When it is desired to return the spring to its first position, the striker then adjacent the spring will be effective to throw the spring, whereas the first-named striker will be inefiective.

Such arrangement lends itself particularly to electromagnetic operation of the strikers, and accordingly, each striker may be associated with an armature system movable responsively to the energization of a solenoid coil. Since both strikers operate simultaneously,- a simple two-wire circuit with a momentary contact single pole push button switch or the like suffices for energizing the solenoid coils.

The action of the tog le spring may be utilized in many ways. In one illustrated embodiment of the invention, contacts associated with the toggle springv cooperate with fixed contacts connected into an electricv circuit to be controlled. Movement of. the toggle spring inone direction brings the. contacts thereof in engagement with said fixed contacts, to provide means for completing the circuit across the fixed contacts;

Fig. 5 is a graphic representation of the oper- I ation of the toggle spring during the stage of throw thereof;

Fig. 6 is a cross sectional view of another form of device operated by the toggle spring actuator comprising the present invention;

Fig. 7 is a top plan View of the same;

Fig. 8 is a section taken on lines 88 of Fig. 6; and

Fig. 9 is an enlarged view of a portion of the toggle spring, showing the attachment of a lever thereto.

Referring to the drawings for a more complete description of the invention, a toggle Spring I is suitably mounted within a housing II of electric insulation material, by supporting the periphery of said toggle spring within a suitable slot or kerf, as shown.

The toggle spring is desirably of the formdisclosed and claimed in my said co-pending application Serial No. 441,382, and comprises concatenated spring systems of which the rim I2 is one system and a legged center portion I4 is the second. Accordingto a preferred method of manufacture of said toggle spring, the rim I2 is dished, and is given a permanent set. The central portion I4 has no permanent set, but is maintained in bowed elastic tension by the dished rim. According to the thickness of the material of the rim and the height thereof related to the plane of the periphery of the rim, hereinafter designated the fulcrum plane of the spring I0 and identified as FP in Figs. 2, 4, and 5, the toggle spring may have one or two positions of stable equilibrium. Mathematically, the condition of a double position of stable equilibrium may be rep resented by the formula h/t 8, wherein it represents the depth or conicity of the rim, and t is the thickness of the material of which the rim is made.

In the illustrated embodiment of the invention, the toggle spring I0 is assumed to have two positions of stable equilibrium.

A feature of a toggle spring made pursuant to the teachings of my said application is that an external force applied to the center of the spring for a distance representing less than one-half of the total distance of throw of spring from one to another of its positions of equilibrium generates sufficient energy forces within the spring to cause the spring to complete its throw under its own power. Preferably, the actuating forces are applied to the geometric center of the spring; in the illustrated embodiment, said center comprises an imperforate substantially circular area I5.

In the present invention, the means for actuating the toggle spring include plungers IS, IT, having strikers IBa, I'Ia respectively disposed on opposite sides of the toggle spring l0, and directed at the center portion I thereof. Each said plunger is movable in'a straight line in the direction of the toggle spring, and each is preferably simultaneously movable in the direction of the spring.

A convenient method of moving the plungers I6, I l is electromagnetically, and pursuant to such arrangement, the said plungers I6, II, are secured to magnetic armatures I8, 28, respectively, said armatures being movable under the magnetic effect of coils 2 I, 22, suitably mounted within shells 23, 24, of electromagnetic material. Each of said shells may be formed with a pole piece 23a, E la respectively, said pole pieces being centrally bored to provide bearing guides for the respective plungers. The entire assembly may be suitably mounted within an external housing 25 of any suitable construction or configuration.

As shown in Fig. 4, the magnet windings are in series in a control circuit C, and are simultaneously energized by the closing of a momentary contact push switch S.

When said magnet windings are energized, each acts simultaneously upon the respective armatures I8, 20, to forcibly drive said armatures and the therewith carried plungers toward the toggle spring l0.

Referring to Fig. l, in which the apparatus is shown in vertical position, the toggle spring I0 is in a convex position, and the striker I6a of freely movable plunger it rests thereon, Whereas the striker Ila of plunger H is resting upon the pole piece E ia. When the magnets are energized, plunger It is pulled downwardly and plunger I1, upwardly. The movement of the plungers, however, is so limited by contact of face [8a of armature I8 and face 29a of armature 28 respectively against the pole-pieces 23a and 2 3a that each has a drive stroke of less than fifty per cent (50%) of the total throw of the spring l0, and hence the striker Ifia will act forcibly upon the spring for a distance which does not attain the fulcrum plane of the spring; whereas the striker IIa will not come into contact with the spring. The movements of the strikers are indicated in broken line in Fig. 1. In View of the throw characteristics of the spring, the forcible movement of striker Ilia thereagainst will cause the spring to move through its dead center position toward its second position of stable equilibrium. Even if the switch S is held in closed circuit position, thereby maintaining the energization of the magnets, and the striker Ila remains in the dotted line position of Fig. 1, the toggle spring III has been given all of the movement necessary to throw through dead center or fulcrum plane. When the control circuit C is opened, the spring ID will continue its throw to occupy the position shown in Fig. 2. The armature and plunger II, by gravity, will drop to said Fig. 2 position.

The next instant of closing of control circuit C and corresponding energization of the magnets will move plunger assembly I! upwardly to impinge upon the spring I0 and will throw it towards its first, i. e., Fig. 1, position. When the magnetic action is terminated, the completion of throw of the spring will lift the plunger system I6, against the action of gravity, to the solid line position indicated in Fig. 1.

The movement of the toggle spring may be utilized in various ways. As a typical instance, the toggle spring and actuating assembly may be employed as an electric circuit breaker, pursuant to which the spring IE] carries electric contacts 30, 30, operatively associated with suitable fixed contacts 3!, 3| of a load circuit L. In the Fig. 1 position, the contacts 3!! are in engagement with the contacts 3|, whereupon the load circuit L is closed. Similarly, Fig. 2 shows the circuit breaker in open circuit position, wherein the concavity of the toggle spring ID has carried the contacts 33 out of engagement with fixed contacts SI.

The respective contacts 30, 3i, make and break with a snap action, as graphically illustrated in Fig. 5, which shows the toggle spring It! at an intermediate stage of flip. The extertion of pressure against the center of the legged spring system has the immediate effect of sharply reversing the angle of slope or conicity of the rim portion I2 of the spring, which rim portion carries the contacts 30.

At the instant of flip of the rim portion, the

center portion I4 is still in substantially its initial convex shape; the energy created within the spring during the stage of flip of the rim whips the center portion through to its final concave shape. Therefore, even though the legged center portion has moved a relatively small distanceestimated to be from twenty-five (25) to thirty (30) per cent of the total distance or" throw of the springthe contact-carrying rim has already snapped sharply into its ultimate position. Obviously, the reverse action occurs when the spring is returned from open circuit position to closed circuit position, and the contacts 30, 3I make with positive pressure and high speed.

Fig. 6 illustrates an application of the toggle spring actuator in a device embodying a mechanical linkage for the actuation of appropriate apparatus. A typical application of such illustrated embodiment may include the throw of a track switch in a toy train system, or similar use wherein a compact actuator of relatively small power requirement will be useful.

In adapting the toggle spring actuator to this purpose, I provide a housing formed of hemicylindrical halves 250, 250a, within which are positioned solenoid coils ZI 0, 220, having suitable casings 230, 240 formed to provide combined pole piece and bearing sleeves 230a, Nile. Strikers I66, I'Iil project from the ends of magnetic armatures IBB and 200, and are directed toward the center portion of double equilibrium point toggle spring I00, the latter being mounted within a suitable kerf as illustrated in Fig. 6.

To the rear of each of the armatures I80, 20! is an extension I60a, Him, to each of which is connected a single equilibrium point toggle spring NH and III, normally biased to move the associated armature-striker system away from the toggle spring I00.

The respective solenoid coils 2m, 2251 are electrically connected in series, as illustrated. Binding posts 2| I and HI provide means for the connection of a control circuit C, which may be served by any suitable source of electric power such as dry batteries or their equivalent.

A single pole momentary contact push switch S closes the circuit and simultaneously energizes each of the armature coils.

When the solenoid coils are energized, the magnetic pull thereof simultaneously draws each armature-striker system in the direction of the toggle switch I; and as previously described, the total elfective movement of each said armature-striker system, after the striker thereof impinges against the toggle spring lilo, is less than one-half of the total throw of the toggle spring. Therefore, only one of said armature-striker systems impinges against the toggle spring at any one conjoint movement of the two systems.

The movement of the armature-striker system is against the bias of its respective associated single equilibrium point toggle spring, and hence when the control circuit is opened, the said single equilibrium point toggle springs mechanically return the armature-striker system to its initial, 1. e., Fig. 6, position.

The action of the double equilibrium point toggle spring I may be mechanically translated to operate any suitable external apparatus, as by the illustrated lever and linkage. Suitably mounted on each of a pair of legs of the central legged portion I40 of toggle spring I00 is an ear MI and operatively associated therewith is a lever I42, bifurcated at its ends for pivotal attachment to said ear, as by the slot and pin connection illustrated in Fig. 9.

Lever I42 extends through a slot I43 in the housing, said slot being formed with oppositely curving walls, see Fig. 6, to provide a suitable pivot point. A link I 44 may be pinned to the lever I42, whereupon the throw of the lever is efiective to drive the link I44 in one or the other direction.

Suitable end caps I45 may be employed to secure the respective halves of the casing and mounting lugs hi6 afford means for supporting the apparatus on any suitable base.

Whereas I have described my invention by reference to specific forms thereof, it will be understood that many changes and modifications may be made provided they do not depart from the scope of the claims.

I claim:

1. In combination with a toggle spring and mounting therefor, actuating means positioned in opposed relationship with respect to said toggle spring and movable with respect thereto, and means whereby each said actuatin means is moved simultaneously in the direction of said toggle spring,

2. In combination with a snap action spring and mounting therefor, plungers positioned on opposite sides of said snap action spring and movable with respect thereto, and means for moving each said plunger simultaneously toward said spring.

In combination, a snap action spring throwable from one position of equilibrium to a second position, a point on said spring travelling over a predetermined path during said throw, a plunger directed at said spring in the zone of said point on each side of said spring, and means for simultaneously moving each said plunger toward said spring.

4. In combination, a toggle spring throwable from one position of equilibrium to a second position over a substantially fixed path of travel, and means for mechanically operating upon said toggle spring for throwing the same, said means including strikers disposed on opposite sides of said toggle spring and moving, after engaging with said toggle spring, for a distance less than one-half of the total throw of said toggle spring, and means for moving said strikers.

5. In combination, a toggle spring throwable from one position of equilibrium to a second position over a substantially fixed path of travel, and means for mechanically operating upon said toggle spring for throwing the same, said means including strikers disposed on opposite sides of said toggle spring and moving, after engaging with said toggle spring, for a distance less than one-half of the total throw of said toggle spring, and remotely controllable means for moving said strikers.

6. In combination, a toggle spring throwable from one position of equilibrium to a second position over a substantially fixed path of travel, and means for mechanically operating upon said toggle spring for throwing the same, said means including strikers disposed on opposite sides of said toggle spring and moving, after engaging with said toggle spring, for a distance less than one-half of the total throw of said toggle spring, and magnetic means for moving said strikers.

7. In combination, a toggle spring throwable from one position of equilibrium to a second position over a substantially fixed path of travel, andmeans for mechanically operating upon said toggle spring for throwing the same, said means including strikers disposed on opposite sides of said toggle spring and moving, after engaging with said toggle spring, for a distance less than one-half of the total throw of said toggle spring, and magnetic means for simultaneously moving said strikers.

8. In combination, a toggle spring throwable from one position of equilibrium to a second position over a substantially fixed path of travel, and means for mechanically operating upon said toggle spring for throwing the same, said means including strikers disposed on opposite sides of said toggle spring and moving, after engaging with said toggle spring, for a distance less than one-half of the total throw of said toggle spring, and simultaneously energized magnetic means for moving said strikers.

9. In combination, toggle spring means movable over a substantially fixed path of travel, a striker operatively associated with said toggle spring and movable in the direction thereof, said striker operating upon said toggle spring means for a distance equal to not more than one-half. of the total movement of said toggle spring, and means for moving said striker in the direction of said toggle spring.

10. In combination, a toggle spring supported at its outer edges, plunger means directed at an unsupported portion of said toggle spring from opposite sides thereof, and means for moving said plunger means toward said toggle spring.

11. In combination, a toggle spring supported at. its outer edges for free movement of a central portion, a plurality of means operable against said central portion from variant directions, to exert pressure thereon, said means being so arranged that only one said means exerts pressure on. said spring at a given instant, and means for moving said first-named means collectively in the direction of said spring.

12. In combination, a toggle spring throwable from a position of equilibrium through a fulcrum plane to a second position, and means for operating upon said toggle spring to effect such throw, said means including a magnetically responsive armature and a plunger movable thereby, said plunger being limited to a travel which approaches but does not attain the fulcrum plane of said spring, and solenoid means for moving said armature.

13. The combination set forth in claim 12, further characterized by the provision of electric contact means operatively associated with said toggle spring and movable thereby, and contact means disposed in such relationship with the first-named contacts that the respective contacts are in engagement in one position of said toggle spring and are out of engagement in a second position thereof.

14. In combination, a toggle spring throwable through its fulcrum plane from a position of stability to a second position, mounting means for said toggle spring, a solenoid positioned on opposite sides of said toggle spring, an armature system movable by each said solenoid, a striker associated with each said armature system and movable thereby toward said toggle spring, said solenoids being in series electrical circuit, and switch means for closing the solenoid circuit for simultaneously energizing each said solenoid.

15. In combination, a toggle spring throwable through its fulcrum plane from a position of stability to a second position, mounting means for said toggle spring, a solenoid positioned on opposite sides of said toggle spring and supported by said toggle spring mounting, an armature system movable by each said solenoid, a striker associated with each said armature system and movable thereby toward said toggle spring, said solenoids being in series electrical circuit, and switch means for closing the solenoid circuit for simultaneously energizing each said solenoid.

16. In an improved toggle spring actuator, the combination with a toggle spring and a lever pivotally mounted thereon, of striker means directed toward the center of said toggle spring from opposite directions, means for simultaneously moving said striker means toward said toggle spring, and a second toggle spring means operatively associated with each of said striker means to return said striker means to initial position after movement thereof toward said first named toggle spring.

WILLIAM E. STILWELL, JR. 

